Process of making mixtures containing bituminous dispersions



Patented Aug. 30, 1938 UNITED STATES PATENT OFFICE PROCESS OF MAKINGMIXTURES CONTAIN- ING BITUMINOUS DISPERSIONS No Drawing. ApplicationAugust 22, 1931, Serial No. 558,846

1 Claim. (01. 106-3 6 Y 77 This application is a continuation in part ofmy co-pending application Serial No. 448,161, filed April 28, 1930 whichlatter in turn constitutes a continuation in part of my applicationSerial No. 313,840 filed October 20, 1928.

This invention relates to aqueous dispersions of substances normallyimmiscible with water, and has more particular reference to dispersionsof bituminous materia l s i r 1 water. *Bltfifirnous dispersions havebeen known for some time and extensive quantities are being producedcommercially at the present time in accordance with certain of thebetter known and more practical methods available in the art. Thesedispersions possess certain well defined properties that are, to aconsiderable extent, governed by the character of the material used asthe dispersing agent. The stabilitypf these dispersions is one of theproperties which plays an important part in their commercialapplication. For certain industrial uses, for example, the dispersion isrequired to be exceedingly stable, while for other uses it may berelatively unstable, and between these extreme limits there are numeroususes to which the dispersions may be applied for which they may be of anintermediate degree of stability. Thus, some of these dispersions havebeen used in the manufacture of waterproof fibrous products, and wherethese processes are carried out on the ordinary paper making machines,it is necessary that tH Elispersion be highly stable in order that itmay not be broken by the mechanical influences to which it is subjectedduring the paper making operation. On the other hand certain of thesedispersions have been adapted for use in the building of roads, whereinit is required that the dispersion be relatively unstable so that whenapplied in a thin layer over the stone or other mineral aggregate thedispersion will very readily be broken on exposure to the air so as toform quickly a partially coalesced film of sufficient continuity torapidly bind the aggregate, etc.

In numerous other instances in the individual application of thesedispersions it becomes necessary to admix with them certain othermaterials, and Where the dispersions are of the comparatively unstablevariety difilculty may be encountered in admixing the other substancestherewith because of the tendency of the latter to break down thedispersions before the admixing has been completed and the dispersionapplied to its intended use. Thus, for example, where it is desired toadmix materials such as asbestos with a soap dispersion of bitumen, thelatter is almost instantly broken down upon the addition of the asbestosthereto. Similarly, lamp black, Portland cement and certain pigmentswhen added td'ii ap' iaiii'ulsions of asphalt break the emulsion almostimm'diat'lyme primary purpose of my 5 present invention is to provide et for enabling various matgrialitg ge readily agg ixeg W1 1 xee weawitbaatsausiaaaj zeekiamdswa o ose dispersions which are, relativelyspeaking, unstable.

I have found, where breaking down of a dispersion is caused by materialadded thereto, that this action is in most instances due to the factthat either the charge upon the particles is reversed by the adde'dniat'eriaI as inthe case of 'lafiiibllack, acid pigments and asbestos,or, as in uieasenr Pomona cement where no substantial change of thecharge upon the dispersed particles is incurred, the added materialcontains polyvalent ions which breakthe emulsion by reacting with th e en ulsifying agentas, for instance,

have found that the foregoing difficulties can be avoided by pretreatingthe material which it sla es.raae irorneeisrasda either'one or 'twoways, depending upon which of the foregoing conditions prevails. Thus,if the condition to be dealt with is one where the added substance has apH value on the opposite side of theisoelectric po'irIFofft he'l"emulsion" so th'af'the' added sub- Steinem have a tendency to reducethe charge upon the particles and cause the charge thereof to approachor pass through the isoelectric point, then the material to be added tothe dispersion is pretreated so as to bring the pH thereof om t l e a sisthe pl l p f tl ie emulsion itself and preferably tfibiit' the pH theifiulsionitself. Methods of incorpora mg such mi'iifials with emulsionsof the soap type are illustrated and claimed in my 40 co-pendingapplication Serial No. 448,161.

0n the other hand, if the condition to be dealt with is one wherein thematerial to be added to the emulsion contains or yields inagueoussolution, dior V polyvalent ions which break the emulsion by reactingwith the emulsifying agent, then the materialniaybe pretreated with anagent of such character andmmm a. mmnni re stance to be cci'fimifiwvtith th e emulsion, b recipitating it into an insoluble compoundt gr eierably less soluble than the insoluble reaction product of the soap andthe ion, or in other instances to repress the formation of ions that mayreact with the soap to form an insoluble comun ere As an example of myinvention and representing an embodiment thereof according to condi- 5tions as .last described, I have been able to produce a mixture of asoap dis rsion of as halt with Portland cement which unher ordinaryconditions would breaE down the dispersion before any substantial mixinghas taken place. Such a mixture of soap dispersion and cement might beemployed with advantage in the production of a mastic floor mix. To thisend alkaline material such as trisodium phosphate may be added insuitable quantities to the Portland cement,

thereby effecting precipitation oi insoluble calwater soluhle calciumlOl'lS present in the Portland cement, with the trisodium phosphate andthus efiecting removal of the water soluble di valent calcium lOIlS rom1e or anfienfentt' ment may comprised? to 39?]; as halt 3Q to 43% ofwater; 1 to 7% soa on the aqueous phase;

excess alkali on the aqueous an cemen retreated asjibove an up to .5%phase. The Portl M described w 7 19s a e, may then h"v'e 1y"'readi lyincorporate in the dispersion without imparing its stability in anyperceptible degree. The flooring mix may then be produced with a soapdispersion of asphalt of the character indicated, by mixing suitablequantities of sand or similar aggregate, with the pretreated Portlandcement and with the asphalt dispersion. ne suc mix which has been consuita e, may consist of one part by volume of the pretreated cement; 2parts by volume of asphalt dispersion and 2 to 4 parts by volumeo'f'fiiie sand. Similarly, lime 'n rocks or mineral aggre- 0 gates, suchas tra rock containing substantial quantities of fines, may besuccessfully coated with bituminous dispersions of the chm above in ca eor the production of premix bitumino rete, by

treating the rock or minera aggregate with quan s of triso'diumphosphatgsufficient to precipitate the ion zahle ca c1um o r other oivalent safltscaii'id therehy and maintain 'e pH hf the reaction productand the system at a sufiiciently high value.

In lieu of alkaline materials, such as trisodium phosphate, I may employneutral salts, such as d1 or monoammonium Phosphate which likewise wouldprecipi a e msou 1e calcium phosphate by interaction with the calciumsalts carried by the Portland cement or mineral aggregates of In lieu ofalkaline or neutral salts, acids or acid salts such as phosphoric acidor so lllIl'l dihydrogen Ehospha e, may e employed and again, in 'sns-ance, the treating material would serve to prciitate a n insolublepolyvaen g -e u e. ere'icids'oracid sa s are emp oye, it is essentialthat the excess alkali carried in the emulsion be suflicient to reventthe acid or acid salt from lowering *Eg p o e emu 510 o a v ueG'X'lfiia'ting isoelectric point of the emulsion, or the treated productto be admixed and brought back to the alkaline side.

In still another embodiment of the invention, I may employ an alkalisuch as sodium or r22 tassium hydroxide to retreat the ma eria to e com1 the emulsion, the hyaroxm ions thus provided, serving to repress theformation of the water soluble dior polyvalent ions which wouldotherwise react with the soap used as the emulsifying agent for thedispersion.

Other substances that may be employed in carrying out the inventioninclude ammonia. ammonium oxalate, ammonium tannate and g; monium carona e.

It is recognized that certain of the substances mentioned herein forcarrying out the invention are more or less decomposable in aqueoussolution upon contact with air. In such cases, while the reagentfunctions to prevent breaking of the emulsion when mixed with thematerial such as mineral aggregate yet decomposition of the reagentafter the mixture such as mineral aggregate coated with the emulsion isExpBsed to'the aftertaste cause the emulsion to revert to unstable formand thereby decreases the time required for the emulsion to coalesceupon the stone or other aggregate.

I claim as my invention:

A process of waterproofing material with an aqueous emulsion of ahydrocarbon waterproofing agent which comprises pre-treating thematerial to be waterproofed with a solution of an emulsion stabilizer,and then mixing the material with a quick-breaking aqueous emulsion of awaterproofing agent substantially free of colloidal powders.

LESTER KIRSCHBRAUN. 55

